Urea finds widespread use as a fertiliser and in industrial chemical manufacture. It is conventionally made by reacting ammonia with carbon dioxide to form a solid product which is often shaped by prilling or granulating. Formaldehyde or a urea-formaldehyde concentrate (UFC) are often used to stabilise the urea before or during the shaping process. UFC is also used as a feedstock for the manufacture of urea-formaldehyde resins.
Formaldehyde is manufactured by the oxidation or dehydrogenation of methanol. There is scope for providing an integrated process in which the production of formaldehyde is integrated with a flowsheet involving the production of one or more formaldehyde-containing precursors or products, leading to more efficient use of energy and/or of feedstocks.
However, the demand for formaldehyde to stabilise the urea from a single production facility is small and beyond the economic feasibility for a dedicated formaldehyde production facility. Due to the small scale of the requirements, the formaldehyde is normally produced at a separate dedicated formaldehyde production facility and transported to the ammonia/urea production facility where it is stored. An integrated urea-formaldehyde process with a dedicated formaldehyde production unit based on a methanol-ammonia co-production process which improves the ammonia productivity and does not reduce urea production therefore has the potential to provide efficiency savings compared with a conventional process